Optical waveguide device

Abstract

An optical waveguide device is provided which can efficiently guide undesired light to the outside of a substrate or the outside of the overall optical waveguides even when optical waveguides are integrated. In the optical waveguide device, an optical waveguide is formed on a substrate, the optical waveguide includes a main waveguide in which signal light propagates and an undesired-light waveguide for removing undesired light from the main waveguide, and the undesired-light waveguide is separated by the main waveguide interposed therebetween at an intersection in which the undesired-light waveguide and the main waveguide intersect each other.

What is claimed is: 
     
       1. An optical waveguide device, comprising: an optical waveguide formed on a substrate, the optical waveguide comprising a main waveguide in which signal light propagates, and an undesired-light waveguide for removing undesired light from the main waveguide, wherein
 the undesired-light waveguide extends from an inside of an area surrounded by the main waveguide to an outside of the area surrounded by the main waveguide, and 
 the undesired-light waveguide is separated into two portions by the main waveguide interposed between said two portions at an intersection in which the undesired-light waveguide and the main waveguide intersect each other. 
 
     
     
       2. The optical waveguide device according to  claim 1 , wherein an intersection angle at which a straight line connecting the two portions of the undesired-light waveguide intersects with the main waveguide is in the range of 3 degrees to 177 degrees. 
     
     
       3. The optical waveguide device according to  claim 1 , wherein a distance between ends of the undesired-light waveguide portions separated at the intersection with the main waveguide is 10 μm or more. 
     
     
       4. The optical waveguide device according to  claim 1 , wherein a width of the undesired-light waveguide portion after the intersection is larger than a width of the undesired-light waveguide portion before the intersection. 
     
     
       5. The optical waveguide device according to  claim 1 , wherein a thickness of the substrate is 30 μm or less. 
     
     
       6. The optical waveguide device according to  claim 1 , wherein the undesired light is higher-mode light propagating in the optical waveguide, or radiation-mode light radiated from a combining portion of the optical waveguide. 
     
     
       7. The optical waveguide device according to  claim 2 , wherein a distance between ends of the undesired-light waveguide portions separated at the intersection with the main waveguide is 10 μm or more. 
     
     
       8. The optical waveguide device according to  claim 2 , wherein a width of the undesired-light waveguide portion after the intersection is larger than a width of the undesired-light waveguide portion before the intersection. 
     
     
       9. The optical waveguide device according to  claim 3 , wherein a width of the undesired-light waveguide portion after the intersection is larger than a width of the undesired-light waveguide portion before the intersection. 
     
     
       10. The optical waveguide device according to  claim 2 , wherein a thickness of the substrate is 30 μm or less. 
     
     
       11. The optical waveguide device according to  claim 3 , wherein a thickness of the substrate is 30 μm or less. 
     
     
       12. The optical waveguide device according to  claim 4 , wherein a thickness of the substrate is 30 μm or less. 
     
     
       13. The optical waveguide device according to  claim 2 , wherein the undesired light is higher-mode light propagating in the optical waveguide, or radiation-mode light radiated from a combining portion of the optical waveguide. 
     
     
       14. The optical waveguide device according to  claim 3 , wherein the undesired light is higher-mode light propagating in the optical waveguide, or radiation-mode light radiated from a combining portion of the optical waveguide. 
     
     
       15. The optical waveguide device according to  claim 4 , wherein the undesired light is higher-mode light propagating in the optical waveguide, or radiation-mode light radiated from a combining portion of the optical waveguide. 
     
     
       16. The optical waveguide device according to  claim 5 , wherein the undesired light is higher-mode light propagating in the optical waveguide, or radiation-mode light radiated from a combining portion of the optical waveguide. 
     
     
       17. An optical waveguide device, comprising: an optical waveguide formed on a substrate, the optical waveguide comprising a main waveguide in which signal light propagates, and an undesired-light waveguide for removing undesired light from the main waveguide, wherein
 the undesired-light waveguide extends from an inside of an area surrounded by the main waveguide to an outside of the area surrounded by the main waveguide, 
 the undesired-light waveguide is separated into two portions by the main waveguide interposed between said two portions at an intersection in which the undesired-light waveguide and the main waveguide intersect each other, 
 an intersection angle at which a straight line connecting the two portions of the undesired-light waveguide intersects with the main waveguide is in the range of 3 degrees to 177 degrees, 
 a width of the undesired-light waveguide portion after the intersection is larger than a width of the undesired-light waveguide portion before the intersection, a thickness of the substrate is 30 μm or less, and 
 the undesired light is higher-mode light propagating in the optical waveguide, or radiation-mode light radiated from a combining portion of the optical waveguide.